The present invention relates generally to continuously variable toroidal transmissions and more particularly to an improvement in the structure of component parts thereof.
Generally, with conventional continuously variable toroidal transmissions, a center portion of an upper link is swingably mounted to a link post through a spherical bearing as disclosed, e.g. in JP-A 4-29659. However, in view of an oscillation center of the upper link located at the spherical bearing, the lengths of right and left portions thereof are not equal to, but different from each other since every point in the diameter of the spherical bearing can be a supporting point, having a bad influence on the shift performance.
In this connection, JP-A 61-124764 proposes the structure for supporting an upper link and an link post by a support pin, which allows an equal movement of right and left portions of the upper link upon shifting, resulting in possible maintaining of the desired shift performance.
Upon assembling of the transmissions, components parts are generally brought into a casing through an opening formed on the side of a lower link, i.e. a lower portion of the transmission. Thus, the solution proposed by JP-A 61-124764 makes assembling of the transmissions practically difficult, resulting in impossible application to real manufacturing of the transmissions.
It is, therefore, an object of the present invention to provide continuously variable toroidal transmissions which can be assembled easily without causing the above inconvenience.